Xsd

Traceability:

Category:Coding

<Orders>
  <Order>
    <OrderNo>18090</OrderNo>
    <Article>09</Article>
    <Data>
      <Column>1</Column>
    </Data>
  </Order>
</Orders>

if you use xs:choice then you may get any order and several element may be several times inside of <Order> but you cannot make some elements to be required

if you use xs:all then you may make some elements to be required and you may get any order but element may be no more than once inside of <Order>

Checking online

http://www.utilities-online.info/xsdvalidation/#.VqoVWbcrKCr